// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/socket/socks_client_socket_pool.h"

#include <utility>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/time/time.h"
#include "base/values.h"
#include "net/base/net_errors.h"
#include "net/socket/client_socket_factory.h"
#include "net/socket/client_socket_handle.h"
#include "net/socket/client_socket_pool_base.h"
#include "net/socket/socks5_client_socket.h"
#include "net/socket/socks_client_socket.h"
#include "net/socket/transport_client_socket_pool.h"

namespace net {

SOCKSSocketParams::SOCKSSocketParams(
    const scoped_refptr<TransportSocketParams>& proxy_server,
    bool socks_v5,
    const HostPortPair& host_port_pair)
    : transport_params_(proxy_server)
    , destination_(host_port_pair)
    , socks_v5_(socks_v5)
{
}

SOCKSSocketParams::~SOCKSSocketParams() { }

// SOCKSConnectJobs will time out after this many seconds.  Note this is on
// top of the timeout for the transport socket.
static const int kSOCKSConnectJobTimeoutInSeconds = 30;

SOCKSConnectJob::SOCKSConnectJob(
    const std::string& group_name,
    RequestPriority priority,
    ClientSocketPool::RespectLimits respect_limits,
    const scoped_refptr<SOCKSSocketParams>& socks_params,
    const base::TimeDelta& timeout_duration,
    TransportClientSocketPool* transport_pool,
    HostResolver* host_resolver,
    Delegate* delegate,
    NetLog* net_log)
    : ConnectJob(group_name,
        timeout_duration,
        priority,
        respect_limits,
        delegate,
        BoundNetLog::Make(net_log, NetLog::SOURCE_CONNECT_JOB))
    , socks_params_(socks_params)
    , transport_pool_(transport_pool)
    , resolver_(host_resolver)
    , callback_(
          base::Bind(&SOCKSConnectJob::OnIOComplete, base::Unretained(this)))
{
}

SOCKSConnectJob::~SOCKSConnectJob()
{
    // We don't worry about cancelling the tcp socket since the destructor in
    // std::unique_ptr<ClientSocketHandle> transport_socket_handle_ will take care
    // of
    // it.
}

LoadState SOCKSConnectJob::GetLoadState() const
{
    switch (next_state_) {
    case STATE_TRANSPORT_CONNECT:
    case STATE_TRANSPORT_CONNECT_COMPLETE:
        return transport_socket_handle_->GetLoadState();
    case STATE_SOCKS_CONNECT:
    case STATE_SOCKS_CONNECT_COMPLETE:
        return LOAD_STATE_CONNECTING;
    default:
        NOTREACHED();
        return LOAD_STATE_IDLE;
    }
}

void SOCKSConnectJob::OnIOComplete(int result)
{
    int rv = DoLoop(result);
    if (rv != ERR_IO_PENDING)
        NotifyDelegateOfCompletion(rv); // Deletes |this|
}

int SOCKSConnectJob::DoLoop(int result)
{
    DCHECK_NE(next_state_, STATE_NONE);

    int rv = result;
    do {
        State state = next_state_;
        next_state_ = STATE_NONE;
        switch (state) {
        case STATE_TRANSPORT_CONNECT:
            DCHECK_EQ(OK, rv);
            rv = DoTransportConnect();
            break;
        case STATE_TRANSPORT_CONNECT_COMPLETE:
            rv = DoTransportConnectComplete(rv);
            break;
        case STATE_SOCKS_CONNECT:
            DCHECK_EQ(OK, rv);
            rv = DoSOCKSConnect();
            break;
        case STATE_SOCKS_CONNECT_COMPLETE:
            rv = DoSOCKSConnectComplete(rv);
            break;
        default:
            NOTREACHED() << "bad state";
            rv = ERR_FAILED;
            break;
        }
    } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);

    return rv;
}

int SOCKSConnectJob::DoTransportConnect()
{
    next_state_ = STATE_TRANSPORT_CONNECT_COMPLETE;
    transport_socket_handle_.reset(new ClientSocketHandle());
    return transport_socket_handle_->Init(
        group_name(), socks_params_->transport_params(), priority(),
        respect_limits(), callback_, transport_pool_, net_log());
}

int SOCKSConnectJob::DoTransportConnectComplete(int result)
{
    if (result != OK)
        return ERR_PROXY_CONNECTION_FAILED;

    // Reset the timer to just the length of time allowed for SOCKS handshake
    // so that a fast TCP connection plus a slow SOCKS failure doesn't take
    // longer to timeout than it should.
    ResetTimer(base::TimeDelta::FromSeconds(kSOCKSConnectJobTimeoutInSeconds));
    next_state_ = STATE_SOCKS_CONNECT;
    return result;
}

int SOCKSConnectJob::DoSOCKSConnect()
{
    next_state_ = STATE_SOCKS_CONNECT_COMPLETE;

    // Add a SOCKS connection on top of the tcp socket.
    if (socks_params_->is_socks_v5()) {
        socket_.reset(new SOCKS5ClientSocket(std::move(transport_socket_handle_),
            socks_params_->destination()));
    } else {
        socket_.reset(new SOCKSClientSocket(std::move(transport_socket_handle_),
            socks_params_->destination(),
            priority(), resolver_));
    }
    return socket_->Connect(
        base::Bind(&SOCKSConnectJob::OnIOComplete, base::Unretained(this)));
}

int SOCKSConnectJob::DoSOCKSConnectComplete(int result)
{
    if (result != OK) {
        socket_->Disconnect();
        return result;
    }

    SetSocket(std::move(socket_));
    return result;
}

int SOCKSConnectJob::ConnectInternal()
{
    next_state_ = STATE_TRANSPORT_CONNECT;
    return DoLoop(OK);
}

std::unique_ptr<ConnectJob>
SOCKSClientSocketPool::SOCKSConnectJobFactory::NewConnectJob(
    const std::string& group_name,
    const PoolBase::Request& request,
    ConnectJob::Delegate* delegate) const
{
    return std::unique_ptr<ConnectJob>(new SOCKSConnectJob(
        group_name, request.priority(), request.respect_limits(),
        request.params(), ConnectionTimeout(), transport_pool_, host_resolver_,
        delegate, net_log_));
}

base::TimeDelta
SOCKSClientSocketPool::SOCKSConnectJobFactory::ConnectionTimeout() const
{
    return transport_pool_->ConnectionTimeout() + base::TimeDelta::FromSeconds(kSOCKSConnectJobTimeoutInSeconds);
}

SOCKSClientSocketPool::SOCKSClientSocketPool(
    int max_sockets,
    int max_sockets_per_group,
    HostResolver* host_resolver,
    TransportClientSocketPool* transport_pool,
    SocketPerformanceWatcherFactory*,
    NetLog* net_log)
    : transport_pool_(transport_pool)
    , base_(
          this,
          max_sockets,
          max_sockets_per_group,
          ClientSocketPool::unused_idle_socket_timeout(),
          ClientSocketPool::used_idle_socket_timeout(),
          new SOCKSConnectJobFactory(transport_pool, host_resolver, net_log))
{
    // We should always have a |transport_pool_| except in unit tests.
    if (transport_pool_)
        base_.AddLowerLayeredPool(transport_pool_);
}

SOCKSClientSocketPool::~SOCKSClientSocketPool()
{
}

int SOCKSClientSocketPool::RequestSocket(const std::string& group_name,
    const void* socket_params,
    RequestPriority priority,
    RespectLimits respect_limits,
    ClientSocketHandle* handle,
    const CompletionCallback& callback,
    const BoundNetLog& net_log)
{
    const scoped_refptr<SOCKSSocketParams>* casted_socket_params = static_cast<const scoped_refptr<SOCKSSocketParams>*>(socket_params);

    return base_.RequestSocket(group_name, *casted_socket_params, priority,
        respect_limits, handle, callback, net_log);
}

void SOCKSClientSocketPool::RequestSockets(
    const std::string& group_name,
    const void* params,
    int num_sockets,
    const BoundNetLog& net_log)
{
    const scoped_refptr<SOCKSSocketParams>* casted_params = static_cast<const scoped_refptr<SOCKSSocketParams>*>(params);

    base_.RequestSockets(group_name, *casted_params, num_sockets, net_log);
}

void SOCKSClientSocketPool::CancelRequest(const std::string& group_name,
    ClientSocketHandle* handle)
{
    base_.CancelRequest(group_name, handle);
}

void SOCKSClientSocketPool::ReleaseSocket(const std::string& group_name,
    std::unique_ptr<StreamSocket> socket,
    int id)
{
    base_.ReleaseSocket(group_name, std::move(socket), id);
}

void SOCKSClientSocketPool::FlushWithError(int error)
{
    base_.FlushWithError(error);
}

void SOCKSClientSocketPool::CloseIdleSockets()
{
    base_.CloseIdleSockets();
}

int SOCKSClientSocketPool::IdleSocketCount() const
{
    return base_.idle_socket_count();
}

int SOCKSClientSocketPool::IdleSocketCountInGroup(
    const std::string& group_name) const
{
    return base_.IdleSocketCountInGroup(group_name);
}

LoadState SOCKSClientSocketPool::GetLoadState(
    const std::string& group_name, const ClientSocketHandle* handle) const
{
    return base_.GetLoadState(group_name, handle);
}

std::unique_ptr<base::DictionaryValue> SOCKSClientSocketPool::GetInfoAsValue(
    const std::string& name,
    const std::string& type,
    bool include_nested_pools) const
{
    std::unique_ptr<base::DictionaryValue> dict(base_.GetInfoAsValue(name, type));
    if (include_nested_pools) {
        std::unique_ptr<base::ListValue> list(new base::ListValue());
        list->Append(transport_pool_->GetInfoAsValue("transport_socket_pool",
            "transport_socket_pool",
            false));
        dict->Set("nested_pools", std::move(list));
    }
    return dict;
}

base::TimeDelta SOCKSClientSocketPool::ConnectionTimeout() const
{
    return base_.ConnectionTimeout();
}

bool SOCKSClientSocketPool::IsStalled() const
{
    return base_.IsStalled();
}

void SOCKSClientSocketPool::AddHigherLayeredPool(
    HigherLayeredPool* higher_pool)
{
    base_.AddHigherLayeredPool(higher_pool);
}

void SOCKSClientSocketPool::RemoveHigherLayeredPool(
    HigherLayeredPool* higher_pool)
{
    base_.RemoveHigherLayeredPool(higher_pool);
}

bool SOCKSClientSocketPool::CloseOneIdleConnection()
{
    if (base_.CloseOneIdleSocket())
        return true;
    return base_.CloseOneIdleConnectionInHigherLayeredPool();
}

} // namespace net
